DIY Twin Paddle Morse Key (UBITX Build Part 2)

I had decided that my UBITX suitcase radio would have a built-in twin paddle (iambic) keyer. I prefer iambic keyers to straight keys, and having it built-in would suit portable operation, i.e. lighter and more convenient. Small paddle keys designed for portable use are available commercially, but they are very expensive. Therefore I thought I would build my own. Although the Morse key described is mounted on the control panel of the radio it could equally be mounted on a separate metal and/or wooden base for general use.

The main requirements were that it would be

• Compact
• Cheap to build
• As close as possible to the ‘feel’ of my trusty Kent twin paddle key.

The Design

I found several examples of DIY keys on the internet using strips of PCB material (copper clad fibreglass) for the paddle arms. The flexing of the board eliminates the need for bearings and springs, therefore making it really simple to construct. If necessary the PCB can be weakened at the pivot point by drilling holes. I did not need to do this as I was using quite thin PCB material. A sketch of my own design is shown below.

 

The pictures below show my prototype. The contact gaps can be adjusted by using different size washers. A more elegant solution would be to fit adjustment screws to each paddle arm but I thought this would be an unnecessary complication. After all, once the gaps are set to my own preference I should not need to adjust them again.

To be continued.

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